The Maximum Likelihood Detector which is also known as the Optimum Noncoherent Detector (or correlation detector) for detecting FSK signals in an additive white gaussian noise channel is well known. The performance of a correlation detector can also be achieved with other detector architectures such as a Matched Filter or a Fast Fourier Transform (FFT). These detectors have the ability to achieve a significant sensitivity improvement (i.e., 4 dB) over that of discriminators for M-level orthogonal signaling (i.e. FLEX.TM.). Traditional baud detectors (i.e., SKUNK detectors) based on edges of the recovered audio signal can not be employed since they do not operate well at the lower sensitivity levels that are achievable by these optimum detectors. This brings the challenge of designing a baud detector that can operate at lower levels. Thus, what is needed is a baud detector algorithm that is capable of detecting all four FLEX.TM. signaling rates (1600 symbols/sec (2 or 4 level) and 3200 symbols/sec (2 or 4 level)) at and above their respective sensitivity levels while rejecting noise, POCSAG, as well as ReFLEX.TM. signals.